It all started while looking for alternatives to LaTeX to write documents and booklets, because since the release of the iPad last year, I wanted to publish in PDF and in EPUB format at the same time, and LaTeX does not offer that option off the box.

And, besides, I really found that LaTeX was a great system, but reading LaTeX code was not always enjoyable. It’s a bit of a messy markup language.

So that’s how I learnt about Pandoc; it is an incredible tool written in Haskell that pretty much transforms any kind of markup into another: RTF, MediaWiki syntax, HTML, LaTeX, Textile, you name it. However, it extends and gives a special status to Markdown, as one of its primary formats, and it provides support to create PDF and EPUB files out of the box; bingo, that’s exactly what I needed. Even better, it uses LaTeX to generate PDF files, which means that I can reuse my LaTeX knowledge to generate beautiful documents.

But then, learning more about Markdown (the syntax is not very far away from Textile, which I knew better), I remembered that StackOverflow uses it; that GitHub uses it; and then I found an excellent Markdown plugin for WordPress and another great Markdown Redmine plugin. Then I updated Elements recently on my iPad (an excellent Dropbox-powered text editor for the iPad), and found out that it had native Markdown support. And of course, both MacVim and TextMate have an excellent Markdown support, including syntax highlighting and preview. And finally, even better, I discovered that MarsEdit supports Markdown natively.

So that’s it, I’m sold. I’m writing almost everything these days with Markdown. And it’s a simple, pure joy.

PS: I’m even considering buying Marked by Brett Terpstra, or even Macchiato (although this last one seems to me a bit pricey).

To use it, just clone the repository, copy the config.yaml.sample file as config.yaml and edit its values inside. Run the script and voilà! A new blog post entry with your del.icio.us bookmarks.

The script can also be helpful to those wondering how to use the XML-RPC interface of WordPress from a Ruby script, or how to use the Net::HTTP library to consume a REST API.

[source:ruby] def get_delicious_bookmarks # Connect to delicious and get updates http = Net::HTTP.new(DELICIOUS_SERVER, DELICIOUS_PORT) http.use_ssl = true req = Net::HTTP::Get.new(DELICIOUS_DATES_PATH) req.add_field(“User-Agent”, DELICIOUS_USER_AGENT) req.basic_auth username, password response = http.request(req) results = response.body [/source]

[source:ruby] def post_to_wordpress(title, text) entry = { :title => title, :description => text } # Connect to WordPress using the XML-RPC interface blog = XMLRPC::Client.new(server, path, port) blog.call(“metaWeblog.newPost”, blogid, username, password, entry, true) [/source]

Enjoy! As usual, the code is released with a BSD license.

• Microsoft: Windows, Internet Explorer, Microsoft Office, and C#.
• Sun: Solaris, HotJava (sic), StarOffice, and Java.
• Apple: Mac OS X, Safari, iWork, and Objective-C.
• Google: Chrome OS, Chrome, Google Docs, and… Go.

Precisely, Go was the last piece that Google had to create in order to fit into the framework above. And it did, with a bright team including Ken Thompson (of Unix and C fame) and Rob Pike (of Plan 9 and UTF-8 fame). With names like that, and with Google’s own funding and infrastructure, it is normal that the media went into a hype frenzy yesterday.

I think, however, that Google’s engineers got tired of what the current and upcoming versions of their “official” programming languages (Java 7, C++0x and Python 3.0) had to offer, and simply came up with a programming language that fits better their needs and expectations. As one of the slides of the TechTalk says, with current languages “You can be productive or safe, not both.”

Features like built-in support for concurrency or garbage collection hide the real true feature behind the language: faster build times with static typing support. This is important for Google from a software economy point of view: they want more productivity from their developers, or, in other words, more bang for their buck, all together with verifiable quality and speed of execution. Go seems to be designed to deliver in these areas. However, Rob Pike is careful to say that the language is experimental, so time will tell if their efforts were worth it.

In any case, it is worth noting that there was a previous programming language called Go! (whose author even wrote a book about it), and after an InformationWeek article revealed this, a petition has started in the Go bug tracking, asking Google to change the name of the language, all in the name of Google’s own “Don’t be evil” motto.

Here it goes:

• First of all, remember that you can always create web apps. It’s worth mentioning that you can avoid the App Store and its quirks altogether; it’s up to you ;) This opens up the possibility of using your preferred server-side technology + JavaScript, and there’s quite a few libraries and tools that will help you create a killer web app: Joe Hewitt’s excellent iUI (yes, he’s the same guy behind the Three20 project), the Tank Engine Rails plugin Rails iUI plugin (Tank Engine does not work very well unfortunately), iPhoney or Eclipse are just some of the alternatives.
• If you like C++, you can choose between the official SDK (yes, you can create iPhone apps with just C or C++), or other alternatives like nui, POCO, Boost or haXe. And apparently, soon you’ll be able to use a Symbian C++ toolkit as well (and who knows, maybe even we’ll get Juce on the iPhone one day too!).
• If you are a Flash and ActionScript developer, you are most probably aware that you can create native iPhone applications using Adobe Flash CS5…
• For C# and .NET developers, there’s MonoTouch, which has received extensive press coverage lately.
• If you want to use Lua, you can use the Wax framework.
• If your idea is to “write once, run anywhere”, and “anywhere” in this context means Android, iPhone, BlackBerry and other mobile platforms, you might want to try rhomobile, Corona, PhoneGap or QuickConnect. The XMLVM project might also interest you, as it consists of a cross-compiler toolchain which can be used with Ruby, .NET, Java and can generate code for many platforms at once.
• Finally, if you are into game development, the quantity of libraries allowing you to create iPhone games is simply astounding, many supporting alternative programming languages: SDL, Unity, SIO2, Torque2D, cocos2d and Game Haxe.
• And of course, there’s the official SDK, with Objective-C and Cocoa Touch all the big buzz around it.

What do you think? Is there any library or programming language that I’ve forgotten in this list? Just leave the name and URL in the comments below.

Update, 2009-11-05: Just found the Swebapps service which allows you to create (very basic) iPhone apps without coding.

Update, 2009-11-24: Here’s a new entry for the growing list of alternative frameworks: Crystal SDK by Chillingo.

Update, 2009-11-25: Another one, in C++ and cross-platform: Airplay SDK.

Having documented iPhone URL schemes for TwitterFon, Twitterrific, Tweetie and Twittelator, I’ve created a project, available in Github, called TwitThis, which helps users choose their preferred Twitter client, and makes it easy to remember the user choice, and to launch the associated application with a single command:

This application has the following features:

• The class TwitterClientManager loads a list list of supported Twitter clients is loaded from a plist file, which can be extended to support more clients in the future;
• Each Twitter client is represented by an instance of the TwitterClient class;
• The user can choose his preferred Twitter client at any time, and launch the application by a simple touch; the TwitterClientManager class stores the selected value in the user settings.

If you have to support several different Twitter clients, feel free to use these classes in your own project! The project, as usual, is available in Github with a liberal BSD license. Enjoy! I’d love to hear your comments below.

bluewoki is a very simple walkie-talkie application, which uses the new GameKit framework available on the iPhone OS 3.0. It is available at the App Store! In English, Spanish and French.

The source code is really simple (around 170 lines of code) and you can get it, as usual, from Github with a BSD license.

Fatal error: Call to a member function on a non-object in /home/user/www/wp-admin/includes/dashboard.php on line 647

This has been reported in the WordPress site but no fix has been provided. I found elsewhere a possible fix, but in my case, the new URL would not be saved at all, and the problem would persist.

I fixed it using a good old method, enabled by Open Source™: editing the code directly; I’m posting it here for those of you who would like to do it, until 2.8.1 is released:

[source:php:firstline(646)] $author = $item->get_author(); if ($author == NULL) { $site_link = “”; $publisher = “Someone”; } else { $site_link = esc_url(strip_tags($author->get_link())); if ( !$publisher = esc_html(strip_tags($author->get_name()))) $publisher = __(‘Somebody’); if ($site_link) $publisher = “$publisher“; else $publisher = “$publisher“; } [/source]

As you might know by now, one of the biggest enhancements (and yet, one of the most obscure) of the newly released iPhone 3GS is the new GPU chipset, which allows developers to create applications using Open GL ES 2.0 (together with Open GL 1.1, which was already available in the first two iterations of the iPhone). This is a major advance, invisible to the end user, which, coupled with the unprecedented performance boost of the iPhone 3GS, opens up the possibility to developers to create applications with new textures and effects, yet unforeseen on this platform.

Given that Xcode does not (yet) bring an Xcode template to play with, and that the OpenGL ES 2.0 Programming Guide book, by Aaftab Munshi, Dan Ginsburg and Dave Shreiner does not (obviously) bring iPhone examples, I have created a project in Github where I will be publishing the code samples in the book, as I progress in the lecture, ordered by chapter, ready to compile and play with.

Enjoy! I’m happy not having to use the word “[REDACTED]“ any more now (there’s the other OS, the bigger cat, but, oh well…)

Update, 2009-06-24: I just found this blog post by the folks of Black Pixel (Daniel Pasco‘s company) with benchmarks about OpenGL ES on the iPhone 3GS… and the first line says it all:

Holy crap, this thing is fast

Update, 2009-06-24: Jeff LaMarche just announced that the authors of the book have published iPhone – compatible code in the book website! That effectively renders this project useless :))

My solution (there might be many others!) consists in the following key elements:

• Avoid loading images right after the RSS feed is parsed; instead, use the -tableView:willDisplayCell:forRowAtIndexPath: delegate method in the controller to trigger the loading of the image for cells that become visible; this ensures that only the cells that are visible will receive the order to load images from the network;
• Use a “model” class for each element of the table, and make the custom UITableViewCell subclass a delegate of this model object; then, the model object is responsible of loading its own image, and will tell the UITableViewCell when done;
• Use the ASIHTTPRequest framework, with a shared download queue in the application delegate, so that all of the requests are properly queued, and network resources are properly used;
• Show feedback to the user with scrolling wheels whenever and wherever appropriate;
• Use the Reachability class from Apple’s own sample code to see if we’re really connected to Flickr, and otherwise show an error to the user.

I have created a sample project, as usual in Github, where I gather RSS data from Flickr’s public feed, and then I download synchronously the preview images of the feed. I even included a very simple Core Animation effect which reminds me of how the iTunes iPhone application allows us to hear previews of the songs we want to buy (the image flips and shows another view “behind”).

Feel free to contribute, fork, enjoy, read, use in your own projects, as you want. As I said, there might be many other (and most probably better) approaches to do this, so feel free to leave your comments below, as usual.

Update, 2009-02-24: I have just been told via Twitter by enormego that two weeks ago they have released another “Facebook strip” in Github! You might want to check it out. Mine is much simpler as far as I’ve seen, in particular I don’t have a custom class for buttons… :)